1.5kg fresh plums (firm, slightly under-ripe)
1.5kg granulated sugar
1 tablespoon lemon juice
A knob butter, about 30g
100ml cold water
Prep:15min › Cook:1hr15min › Ready in:1hr30min
Wash plums and remove stalks. Use a fruit knife to cut the plums in half (vertically), then twist to open and remove the stone.
Place fruit, lemon juice and water in a large, deep, heavy based pot and bring to the boil, stirring frequently.
Reduce heat and simmer until the plums have softened, about 40 mins.
Keep on low heat and add sugar. Stir continuously until sugar has dissolved.
Stir in the butter to help reduce frothing. Turn up the heat and stir continuously until the mixture comes to a rapid boil.
Continue stirring on high heat until the jam reaches setting point. If you don't have a jam thermometer - this is obvious when the mixture starts to stick/set on the sides of the pan or starts to set when you drop it from your wooden spoon.
Remove from heat. To test - place a teaspoon of jam onto a cold saucer. Allow to cool, then push your finger through the jam, it should start to congeal and wrinkle up - if you can push your finger through and its still runny, you haven't yet reached setting point. If still not set, return the pot to the heat; bring back up to a rolling boil and test again in a few minutes.
Remove from heat and pour gently into clean, sterilised, warm jars. Check for air bubbles and remove. Seal and label while jars are warm. Allow to cool completely, then store. Yum!
This jam is easy, uses equal quantities of fruit to sugar. So, whether you have a small or a large amount of fruit, its easy to adjust amounts needed. The recipe amount I used (1.5kg fruit to 1.5kg sugar) yielded around 2.5kg jam (5lb).